Enteral nutrition is achieved through naso-esophageal intubation of a feeding tube. Typically, the enteral feeding tube is connected to a container, such as a flexible bag similar to that disclosed in U.S. Pat. No. 4,529,102.
Recently, shape retentive containers have been successfully utilized in enteral feeding therapy, such as the shape retentive paperboard cartons disclosed in U.S. Pat. No. 4,287,247 and sold under the trademarks TETRA PAK, TETRA BRIK, and BRIK PAK. Such cartons are pre-filled with enteral nutritional fluid and then sealed. However, to administer enteral solutions from such cartons, it is necessary to utilize a device which can aseptically access the fluid contents of the carton without leakage and deliver such fluids at a controlled rate.
One such device is a dual spike fluid dispensing column disclosed in U.S. Pat. No. 4,699,296. However, this fluid dispensing device requires use of a rigid cradle structure to support and suspend the carton in a particular angular orientation in which the carton has a single uppermost corner and a single lowermost corner. This cradle is expensive to manufacture and complicates set up of an enteral feeding administration system. In addition, this fluid dispensing device punctures the container near the bottom of one front panel raising a possibility of fluid leakage from the puncture site.
Another dispensing device is disclosed in U.S. Pat. No. 4,655,763 for a vented tubular dispensing spike which removably receives a pH testing indicator. Unlike the dual spike device in U.S. Pat. No. 4,699,296 which provides visualization of fluid level within the shape retentive container by means of a transparent dispensing column, the tubular dispensing spike disclosed in U.S. Pat. No. 4,655,763 has no means for fluid level visualization. Fluid level visualization is necessary because shape retentive containers, such as BRIK PAK cartons, are non-transparent. As a result the volume of fluid and fluid level in the carton is unknown to a user.
Further, the dispensing spike of U.S. Pat. No. 4,655,763 achieves container venting through a separate vent tube externally secured to the dispensing spike. As a result, a larger opening is created in the container by the dispensing spike thereby increasing the possibility of fluid leakage.
Hence, prior to the present invention, a need existed for a unitary spike for aseptic topside access and dispensing of enteral feeding fluids from a shape retentive, pre-filled container, such as a BRIK PAK carton, in which an ambient air vent means was integrally formed within the spike to minimize the size of the spike opening and avoid leakage. A need further existed for a unitary dispensing spike which provided a "sight chamber" for visualization of fluid volume and level within the container. Finally, a need existed for a unitary dispensing spike which would permit passive delivery of fluids through siphon action or gravity feeding.